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-Publisher SEC
-Name Regulation S-X (SX)
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-Article 12
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Note 11 - Derivative Instruments (Details Textual) $ in Thousands, $ in Millions, $ in Millions	1 Months Ended	6 Months Ended
	Jul. 31, 2019 oz $ / shares	Jun. 30, 2019 USD ($)	Jun. 30, 2019 CAD ($)	Jun. 30, 2019 USD ($)	Jun. 30, 2019 MXN ($)
Maximum Allocation of Forecasted CAD-demonimated Operating Costs			75.00%	75.00%	75.00%
Forecasted CAD-denominated Operating Costs to be Hedged, Term		5 years
Accumulated Other Comprehensive Income (Loss), Cumulative Changes in Net Gain (Loss) from Cash Flow Hedges, Effect Net of Tax, Ending Balance				$ 1,000
Foreign Currency Cash Flow Hedge Gain (Loss) to be Reclassified During Next 12 Months				300
Foreign Currency Cash Flow Hedge Gain (Loss) Reclassified to Earnings, Net		$ (700)
Derivative, Net Hedge Ineffectiveness Gain (Loss)		$ 0
Derivative Liability, Fair Value, Amount Not Offset Against Collateral, Total				1,700
Derivative, Fair Value, Obligations Under the Agreements				1,700
Foreign Exchange Contract [Member] \| Other Current Assets [Member]
Derivative Asset, Current				600
Foreign Exchange Contract [Member] \| Other Noncurrent Assets [Member]
Derivative Assets, Noncurrent, Total				500
Foreign Exchange Contract [Member] \| Other Current Liabilities [Member]
Derivative Liability, Current				600
Foreign Exchange Contract [Member] \| Other Noncurrent Liabilities [Member]
Derivative Liability, Noncurrent				$ 1,100
Foreign Exchange Contract [Member] \| Casa Berardi [Member] \| Minimum [Member]
Derivative, Forward Exchange Rate			1.2702	1.2702	1.2702
Foreign Exchange Contract [Member] \| Casa Berardi [Member] \| Maximum [Member]
Derivative, Forward Exchange Rate			1.3332	1.3332	1.3332
Foreign Exchange Contract [Member] \| Casa Berardi [Member] \| Designated as Hedging Instrument [Member]
Derivative, Number of Instruments Held, Total			127	127	127
Derivative, Notional Amount			$ 283.2	$ 218,500
Derivative, Notional Amount1				$ 12,000
Foreign Exchange Contract [Member] \| San Sebastian [Member] \| Minimum [Member]
Derivative, Forward Exchange Rate			20.2420	20.2420	20.2420
Foreign Exchange Contract [Member] \| San Sebastian [Member] \| Maximum [Member]
Derivative, Forward Exchange Rate			20.8550	20.8550	20.8550
Foreign Exchange Contract [Member] \| San Sebastian [Member] \| Designated as Hedging Instrument [Member]
Derivative, Number of Instruments Held, Total			14	14	14
Derivative, Notional Amount				$ 3,300	$ 67.3
Silver Contracts [Member] \| Subsequent Event [Member]
Derivative, Nonmonetary Notional Amount, Mass \| oz	8,600,000
Derivative, Average Price Risk Option Strike Price \| $ / shares	15.13
Gold Contracts [Member] \| Subsequent Event [Member]
Derivative, Nonmonetary Notional Amount, Mass \| oz	194,000
Derivative, Average Price Risk Option Strike Price \| $ / shares	1,400
Commodity Contract [Member]
Derivative Asset, Current				5,900
Derivative Liability, Current				4,000
Unsettled Concentrate Sales Contracts [Member]
Derivative Assets, Noncurrent, Total				1,200
Forecasted Future Concentrate Contracts [Member]
Derivative Liability, Current				$ 2,000